code: def __init__(self, item):
      Exporter.__init__(self, item)
      tr = self.getTargetRect()
      self.params = Parameter(
          name="params",
          type="group",
          children=[
              {
                  "name": "width",
                  "title": translate("Exporter", "width"),
                  "type": "float",
                  "value": 0.1,
                  "limits": (0, None),
                  "suffix": "m",
                  "siPrefix": True,
              },
              {
                  "name": "height",
                  "title": translate("Exporter", "height"),
                  "type": "float",
                  "value": (0.1 * tr.height()) / tr.width(),
                  "limits": (0, None),
                  "suffix": "m",
                  "siPrefix": True,
              },
          ],
      )
      self.params.param("width").sigValueChanged.connect(
          self.widthChanged
      )
      self.params.param("height").sigValueChanged.connect(
          self.heightChanged
      )
  
file_path: pyqtgraph/pyqtgraph/exporters/PrintExporter.py
imports: from ..parametertree import Parameter
  from ..Qt import QtCore, QtGui, QtWidgets
  from .Exporter import Exporter
label_desc: Use image node_id 1 to create a new PrintExporter object from inherited base classes: Exporter with example: obj = PrintExporter(item)